The present invention relates generally to the field of retractable utility knives. More particularly, the invention relates to a utility knife which integrates the blade adjustment feature with the fastener mechanism used to assemble the knife.
Utility knives with retractable blades are well known and versatile tools which include the safety feature of enabling the blade of the knife to be retracted into the body of the knife by the user when not in use. Utility knives often include two body pieces connected together by at least one fastener. Utility knives with retractable blades typically include an actuator connected to a blade carrier. The actuator normally outwardly extends from one of the body pieces to enable a user to manipulate the actuator and thereby adjust the extension or retraction of the blade with respect to the body pieces of the knife.
Existing utility knives with replaceable blades, however, have a number of drawbacks. Utility knifes typically include at least one fastener which requires the use of a tool, such as a screwdriver, in order to remove or install the fastener and to execute replacement of the blade. Existing utility knives typically include an actuator mechanism which is separate from the fastener. Such actuator mechanisms also frequently require the use of a tool, such as a screwdriver, in order to adjust the position of the actuator, and therefore the position of the blade, with respect to the body of the utility knife. Conventional utility knives require the manipulation of the fasteners and the actuator mechanism in order to fully operate the knife. The incorporation of a separate actuator mechanism into such a utility knife increases the complexity as well as the design and manufacturing costs of the knife.
Thus, there is a continuing need for a utility knife having a blade which can be safely and easily replaced and also adjusted without the use of tools. What is needed is a utility knife which combines the actuator mechanism of the knife with the fastener of the knife in order to simplify the design and reduce the overall costs of producing the knife.
According to a principal aspect of the invention, a utility knife for retractably retaining a replaceable blade includes a body, at least two detents connected to the body and a blade adjusting, knife retaining fastener mechanism. The body has first and second portions and a major longitudinal dimension. The first and second portions each have a proximal end, a distal end and a longitudinally extending blade adjustment slot disposed between the proximal end and the distal end. The proximal end of the first portion is coupled to the proximal end of the second portion. The first and second portions define a cavity for storing at least a portion of the blade. The blade adjusting, knife retaining fastener mechanism extends through the blade adjustment slots of the first and second portions and is coupled to the blade. The fastener mechanism is configured to releasably connect the distal ends of the first and second portions of the body. The fastener mechanism is configured to releasably engage at least one of the detents and to adjustably extend along the blade adjustments slots. Each engagement of the fastener mechanism to one of the stops defines a distinct position of the blade with respect to the body.
According to another aspect of the invention, a utility knife for retractably retaining a replaceable blade includes a body, locking means coupled to the body, and blade adjusting means. The body has first and second portions and a major longitudinal dimension. The first and second portions each have a proximal end, a distal end and a longitudinally extending blade adjustment slot disposed between the proximal end and the distal end. The proximal end of the first portion is coupled to the proximal end of the second portion. The first and second portions define a cavity for storing at least a portion of the blade. The blade adjusting means extends through the blade adjustment slots of the first and second portions and is coupled to the blade. The blade adjusting means is configured to releasably engage the locking means to define at least two discrete positions of the blade with respect to the body. The blade adjusting means is configured to releasably connect the distal ends of the first and second portions of the body.
According to another aspect of the invention, a utility knife adapted to enable a user to extend and retract a replaceable blade from the knife includes first and second portions, a blade carrier, at least three detents and an adjustable fastener. The first and second portions each have a first end, an open second end and a blade adjusting slot disposed between the first and second ends. The first end of the first portion is pivotally coupled to the first end of the second portion. The first and second portions form an internal cavity. The blade carrier is disposed within the cavity. The blade carrier is adapted to retain the blade and to move along the cavity between the open and closed ends of the first and second portions. The three or more detents are connected to the first portion or the second portion. The adjustable fastener couples the open second ends of the first and second portions together. The adjustable fastener extends through the blade adjusting slots of the first and second portions. The adjustable fastener is configured to releasably engage at least one of the detents to define at least three discrete positions of the blade with respect to the body. The adjustable fastener is configured to enable the user to connect the second ends of the first and second portions without the use of tools and to enable the user to adjustably position the blade with respect to the body in at least three discrete positions without the use of tools.
Various advantages and features of the invention will be readily apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings described below.